What is USB Debugging and why do you think you need to enable it?? Most of the android phone come with USB debugging been turned off. USB debugging mode mostly use by developer and it allows you to connect your android phone with computer thru Android SDK. Summary, your computer can talk to your android phone and do some development work. By having it enabled, you can flash your custom ROM, your 3rd party control program from your PC to phone, or some others tools like CWM Recovery, rooting tool, and so on. Below is the simple tutorial to guide you how to enable USB debugging mode on Ice Cream Sandwich Android 4.0+ & Gingerbread Android 2.3.
How To Enable USB Debugging Mode On Android 4.0+
2. Press the Developer options box.
3. Check on the USB Debugging / Android Debugging mode.
How To Enable USB Debugging Mode On Android 2.3+
1. Goto Settings –> Applications
2. Goto Development
3. Check on USB debugging/Android debugging mode.